>>132909496The characters are lazy cliche cutouts, lacking any well done quirks or amazing story utilization to hook you on them. Their build up, while not nonsensical or completely nonexistent, is overly simple, rushed, and generally following a very lazy, cookie cutter path.
You don't get the sense that they're taking you towards anything that you haven't seen done better a hundred times before. Furthermore, it's tough to imagine just about anyone in this show living out functional daily lives, not because "they're so accustomed to war" or some crap, but because their archetypes completely define how they behave all the time, and genre cliches define most of their relationships. There are some additional relationship facets that are brought up from time to time, but the writer doesn't really make use of them, which makes them little more than footnotes describing how he wants you to see the relationships.
As an example, how has Mitsuba's "he's like I used to be, but he somehow didn't fuck it up because he's the main character of a shounen manga" been utilized? She continued in her tsundere practices, made some frustrated observations that she's not very competent (not doing much of anything with this, even though it's been a while since the development happened; given their track record, we can probably expect some half baked tactical victory in a major fight which redeems her), and acquired friendship power. That's not good character development. That's taking a potentially decent foundation for an interesting character and then completely botching the execution, which is pretty much OnS's character writing in a nutshell.